Facsimile recorder



y 1956 G. H. LEONARD 2,743,990

FACSIMILE RECORDER Filed Aug. 8, 1952 2 Sheets-Sheet l FIG.1.

.IHZ 31B 49 g 37- F: 56 vF INVENTOR. GEORGE H. LEONARD BY (5 G .2)

A T TORNLY May 1, 1956 G. H. LEONARD FACSIMILE RECORDER 2 Sheets-Sheet 2 Filed Aug. 8, 1952 INVENTOR. GEORGE H.LEONARD Y B C5. Gu /34,

ATTORNEY United States Patent FACSIIVHLE RECORDER George H. Leonard, Darien, Conn., assignor to Faximile, Inc., New York, N. Y., a corporation of Delaware Application August 8, 1952, Serial No. 303,439 11 Claims. (Cl. 346-101) This invention relates to electrical facsimile recorders and particularly concerns apparatus adapted for recording continuous copy.

In certain facsimile recorders of the type employing a rotatable helical electrode in association with a flexibly mounted linear electrode or printer blade with interposed electrolytic recording paper it is desirable to effect recording at high speeds. The rate of rotation of the helical electrode determines the rate of recording and for high speed recording the helix must necessarily rotate at high speed. This high speed operation requires that the associated printer blade fulfil certain requirements. Firstly, a low mass and stiff springing is required to keep the inherent mechanical resonant frequency of vibration of the printer blade as high as possible. This is necessary since the rotating helix provides a relatively strong periodic exciting force. As the helix rotation rate approaches the resonant frequency of that part of the system in a position to be excited by its motion, the printer blade intermittently loses contact with the recording paper and helix and causes printing discontinuities. Secondly, it is necessary to avoid damaging the recording paper during high speed recorder operation. Since the rotating helix and linear printer blade are usually provided with knife-like edges which are in contact with the recording paper during recording, high speed operation of the helix causes an increasingly high approach velocity of helix to blade, building up increasing instantaneous knife edge contact pressures, and resulting in paper puncturing and shredding. To prevent this damage to paper requires low spring pressure between printer blade and helix and more particularly low mass in the vicinity of the area of contact. Thirdly, it is necessary to provide a large volume of ferric material which is consumed during the electrolytic recording process. This necessitates a comparatively large mass of material in the blade which adds to the blade mass and through its stiffness tends to involve increasingly larger portions of the blade directly with the damaging helix action. The necessity of supplying this large mass militates against the requirements above mentioned for low mass stiff springing, and low spring pressure. Fourthly. to produce satisfactory recorded copy the printer blade must present the effect of a rigid, straight, immovable line to the helix to produce geometrically acceptable copy. Fifthly, the effects of erosion of the printer blade on registration with recorded copy and changes in the geometry of recorded copy must be minimized. Sixthly, the geometry of approach of printer blade to helix must be such that paper shredding is avoided. Seventhly, the printer blade must be relatively simple to fabricate and easy to maintain in operation.

The foregoing printer blade requirements for successful high speed facsimile recording are not all satisfactorily met by any printer blade heretofore known. In the present invention all the aforementioned requirements are met by employing a novel flexible linear electrode structure in the form of an endless ribbon, blade, or loop. The loop 2,743,990 Patented May 1, 1956 has a relatively large mass as a whole and is so mounted that the material immediately aifected by the helix motion is small (one-inch approximately). An array of individual springs assures adequate local pressure, and the combination thus has a small mass-to-spring ratio. An angular contact between loop blade and helix is employed which allows adequate flexibility, allowing movement of localized mass elements rather than entire blade movements. The aforesaid angular contact allows a thinner and more flexible material to be used in the blade. The small mass immediately affected by periodic helix movement assures low damage at impact. The useful volume of the blade has been increased in the order of 10 to 20 times over known type blades. A blade originally onehalf inch wide for example, may be used until it is reduced to approximately three sixteenths of an inch. In the novel blade herein disclosed, the line of contact presented to the paper by the angular mounting is stable, since the straight edge opposite the printing edge is rigidly backed up. The manner of backing up does not interfere with the blades flexibility. The blade presents parallel recording lines. During operation the loop blade is continuously in motion resulting in even distribution throughout the entire blade length so that no terminal geometry changes occur. Provision is made for maintaining the eroded edge at a constant position by means of an automatic spring-loaded ribbon po-sitioner. Since the loop blade contacts the helix angularly, the contacting edges of the rotating helix and moving printer blade do not cut the paper even at high rotation speeds. A novel means for moving the printer blade is also disclosed herein. The arrangement of essential parts of the recorder and particularly the loop blade and associated parts is relatively easy to maintain and may be economically manufactured.

It is therefore a principal object to provide means for increasing the usable life of an expendable electrode.

It is a further object to provide a novel loop electrode structure for a recorder.

It is a further object to provide novel means for driving a movable loop electrode.

It is another object to provide an apparatus capable of high speed recording of continuous copy.

Other and further objects and advantages of the invention will become readily apparent from the following description and figures of the drawing.

Fig. 1 is a plan view of a recording apparatus embodying the invention.

Fig. 2 is a side view of the apparatus of Fig. 1.

Fig. 3 is a sectional view taken on lines 33 of Fig. 1.

Fig. 4 is a sectional view taken on lines 4-4 of Fig. 1.

Fig. 5 is a sectional view taken on lines 5-5 of Fig. 1.

Fig. 6 is a showing of the mode of action of the loop electrode of Fig. 1 in accordance with the invention.

Fig. 7 is a perspective view of a novel means for mounting and driving a loop electrode.

Fig. 8 is a plan view of a portion of the arrangement of Fig. 7.

Fig. 9 is a fragmentary sectional view of the loop electrode of Fig. 7, mounted in accordance with the invention.

In Figs. 1 and 2 is shown an endless ribbon-type loop blade 10 mounted on pulleys 11 and 12. The pulleys are mounted on the upper portion 13 of a cabinet 14. The cabinet 14 has a base portion 15 to which top 13 is attached by hinge 16 and latches 17, 18. In base 15 is a compartment 19 for housing a roll of paper 20. One wall of compartment 19 has two sections 20, 21 spaced slightly apart to leave a slit 22 through which recording paper 23 is fed. Paper 23 is fed from roll 20 over feed roller 24 and through slit 22 to a cylindrical drum 25 rotatably mounted on shaft 25'. Drum aver-5,990

25 has a helical electrode 26 mounted on supporting member 27 to raise the electrode 26 above the surface of the drum. Paper 23 is fed between drum 25 and one edge 28 of the loop blade 15). The paper 23 is then passed between paper drive rollers 23 and 3b. The showing of paper 23 is omitted from Fig. l in order to expose the various portions of the recorder in cabinet 14 but is shown by dotted lines in Fig. 2. Pulleys 11 and 12 are supported on shafts 31, 32 and rotate in brackets 33, 34 attached to the top T13 of cabinet 14. of the lower portion of loop blade ll] is positioned at an angle of about 45 to the plane of paper 23 as fed to the blade. The plane of paper 23 is substantially tangential to drum 25 and helix 26. A rigid Ushaped member 35 is located in the top 13 of cabinet 14-. The member 35 has a base bar 36 with arms 37, disposedperpendicular to the base bar. A plurality of intermediate flexible arms 3% it}, 41, 42 are attached to base 36 by suitable means such as screws and nuts 43, 44; see Figs. 3 and 4. At the end of each of arms 3942 is a headed pin 45 which abuts the edge 46 of blade ll) opposite the marking edge 28. A pair of springs 47, 48 applies tension to the member 35 and presses the pins 45 firmly into engagement with the edge 45 of blade iii. Springs 47, 48 attached to pins 49, St? at one end and to pins 51, 52 on base 36 at the other end. Pins 49, b are firmly attached to the sides of cabinet top 13. A pair of triangular shaped members 53, 5d overlie the arms 37 and 38; see Fig. 5. The members 53, 54 are attached to cabinet top 13 by posts 55, 56, 57, 53. The

members 53, 54 each have a headed pin 59 near the top of underside es. Blade rides between pin 59 and the stepped end 61 of arms 37, 38. A headed pin 62' projects from the underside of each of members 53, 54 and through slots 63 in arms 37, 33. The pins 62 allow freedom of movement of member 35 only in the plane of the member. The undersides of members 53, 54 are undercut to allow room for blade it). A comb-like member 54 is positioned under arms 39-42 of member 35. Member 64 is formed of a flexible material and has a plurality of spring fingers 65. Each of fingers 65 is bent slightly as shown in Figs. 3 and 4. A small dimple 65' is pressed out at the end of each of spring fingers 65 and bears on the blade 1i) adjacent to the marking edge 23. Member 64 is attached to a bar 66 by screws 64. Bar 66 is attached to the sides of cabinet top 13. A motor 67 is provided to drive the drum 25, paper roller 3i) and pulley 12 in coordination with each other. On the shaft 68 of motor 67 is mounted a worm 69 and bevel gear 79. Worm 6% drives worm gear $1. Worm gear 81 is carried by a shaft 85) which also carries gear 33 and bevel pinion gear 73. Shaft hit is supported by bearing brackets '77, 82 on cabinet base 15. A bevel pinion gear 79 is mounted on the end of shaft 32 attached to pulley 12. As motor 67 drives worm 69, the gear train drives blade lit) slowly over pulleys l1 and 12. The preferred direction of motion for blade it? is perpendicular to the direction of movement of paper 23 and in a direction opposite to the direction of movement of the locus of contact of the helix 26 and marking edge 23 of blade When blade it? is moving in the preterred direction, paper wrinkling is minimized and the graphic recording is clearer. At the same time paper roller St is driven via gear 84 which engages gear 83 on shaft The bevel gear 79 drives bevel gear 71 which is carried by shaft 72 supported in bearing brackets 75, 76. Gear 73 on the end of shaft 72 engages gear 74 which causes rotation of drum 25. The gear arrangement described is only exemplary since many other arrangements may be readily devised to efiect coordinate movement of blade it), paper 23 and helical electrode 26.

in Fig. 3 is shown the relative disposition of blade 16 and drum when helical electrode 26 is out of contact with the edge 28 of blade lit. The blade 10 is then The list side t pressed by the spring fingers 65 on to the top inclined side of a support plate 86. Plate 8b is attached to another plate $7 carried by the panel 88 on cabinet top 13. As drum 25 rotates the helical electrode 26 is brought into contact with edge 28 of blade 10 as shown in Fig. 4. The blade it is then raised from the top of support plate 86. The arms 39, 4%, 41, 42 although very flexible are strong in the direction of their lengths. They serve to press the edge 28 of blade 10 against the fixed pins 59 in comes of parties-.211 importance as blade members 53, 54. Between pins 59 the flexible arms serve to back up blade lit to prevent backward movement of the blade during recording. This backing action beit) becomes narrower due to erosion during recording. The backing action is produced under tension of springs 47 and 48 and is so directed that flexibility of blade 1i? is not impaired during recording.

In Fig. 6 is shown the manner in which blade 1d flexes as drun 25 rotates and electrode 26 moves across the edge of blade it). Only the spring fingers immediately adjacent to the point of contact of helical electrode 26 and blade move outwardly. The remainder of the spring fingers press lightly on blade Ill) and are undisturbed. Thus only about an inch or so of blade it) is instantaneously subject to movement as electrode 26 moves across the blade. The small mass of the short section of blade ll subject to movement permits very rapid rotation of drum 25 while insuring that close, continuous physical contact of printing edge 28 to helix 26 is maintained. The total mass of the blade lltl is effectively broken up instantaneously into small mass elements having small inherent inertia and very high resonant frequencies. Thus the pounding effect of the rotating helix against the mass of stationary blade parts which damages the recording paper in conventional recorders, is herein avoided.

The present invention contemplates use of electrolytic type recording paper. It is of course adapted to use in recorders employing other types of recording paper. The roll of paper 20 is disposed in compartment 19 to which access is afforded by raising cabinet top 13. When top 13 is raised, gear 79 becomes disengaged from gear 78. This arrangement of the gear train is particularly convenient when access is desired to the underside of cabinet top 13 and to the component members in base 15.

in operation the recording paper is slowly moved past the marking edge of the loop electrode in coordination with the rotation of the drum and movement of the loop electrode. As the drum rotates the locus of contact of the helical and loop electrodes sweeps along the drum while an electric current passes between the electrodes marking the paper with the received facsimile message. The recording operation causes gradual erosion of the marking blade. This erosion is evenly distributed throughout the length of the blade since the blade is constantly in motion during recording. Although blade 14) tends to be pushed aside once for each revolution of drum 25 as helix 26 contacts printing edge 28, the small mass to spring ratio of parts subject to movement assures uninterrupted physical contact of blade and helix at even unusually high rotational speeds. The arrangement of the mounting of blade Eli) and associated parts is such that great stiffness is presented by the blade in the direction parallel to its face so that geometrically straight and parallel recording lines are produced on the recording paper without interfering with the flexibility of the blade in another direction. The angular disposition of blade 1i) insures that full advantage is taken of the flexibility of the blade.

if desired a small metallic spring bafile strip B (Fig. 4) resistant to wear may be interposed between helix 26 and blade marking edge 28 at the point where contact first takes place during each revolution of helix 26. This bafile str p will tend to absorb the shock of initial confact which occurs between helix 26 and blade once each revolution.

In Fig. 7 is shown a modified arrangement for the loop electrode. Loop blade 10 is mounted between two groups of three rollers each. In one group rollers 91, 92 are idler rollers and roller 90 is a drive roller operated by a suitable driving means not shown. In the second group rollers 94, 95 are idler rollers disposed at the sides of the loop corresponding to outside rollers 91, 92. Idler roller 93 is inside the loop as is roller 99. The placement of rollers is such as to insure parallel movement of the straight sides of blade 10'. As shown in Fig. 8 rotation of roller 90 causes movement of the loop 10' in the direction shown by the arrows. The bending stiffness of the blade 10 provides the driving friction necessary to move the blade between the rollers. The diameters of rollers 90, 93 are equal and slightly larger than the spacing between rollers 91, 92 and 9d, 95 respectively. This insures that the sides of the blade remain stiff and in firm contact with the rollers. Spaced slightly from each end of blade 10' by spaces S are stationary friction surfaces 96, 97. If unequal movement or slippage occurs at the sides of drive roller 90, one end of blade 10' contacts friction surface 96 or 97 which prevents blade 10' from being extruded out of the rollers.

In Fig. 9 blade 10' is shown mounted for operation in a manner similar to blade 10 in Fig. 3. An additional cover member 98 is provided. This member has a curved top in which is a felt channel shaped member 99. The member 99 engages the top edge of blade 10' and serves to wipe the blade clean as it is moved between the rollers.

The blade arrangement of Figs. 7, 8, 9 has several advantages over that shown in Figs. 1 to 4. In this arrangement the sides of the loop may be disposed closer to each other making a more compact installation. The large end pulleys of Figs. 1, 2 are eliminated making the mounting arrangement simpler and more economical. No adjustable pulley centers are required since the sides of the blade are self-aligning. The blade is easier to install since there are no parts to change and a blade may be used having more liberal tolerances in dimensions.

While several forms of the invention have been shown and described herein, it will be readily apparent to those skilled in the art that various modifications may be made without departing from the spirit of the invention or the scope of the appended claims.

What is claimed is:

1. A recorder comprising a rotatable rigid electrode, means supporting an elongated flexible blade in contact with said electrode for marking a recording medium therebetween, a plurality of spring loaded arms disposed parallel to one side of the blade pressing the blade against the electrode in a direction parallel to the face of the blade, and a plurality of closely spaced spring elements disposed parallel to and along the face of the blade and pressing the face of the blade in a direction perpendicular to the face of the blade.

2. In a recorder, a vibratable substantially fiat faced linear electrode and a plurality of flat spring elements closely spaced to each other, said elements being disposed substantially parallel to the flat face of the electrode and directing pressure perpendicular to the flat face thereof to limit vibration to a short section of the electrode.

3. In a recorder according to claim 2 wherein said spring elements are joined to form a comb-like member having a plurality of flexible fingers.

4. A recorder comprising a rotatable rigid electrode, means supporting a flat vibratable linear electrode in contact therewith for marking a recording medium therebetween, and a plurality of fiat spring elements closely spaced to each other, said elements being disposed substantially parallel to the fiat face of the linear electrode and directing pressure perpendicular to the flat face thereof to limit vibration to a short section located at the point of said contact.

5. A recorder comprising a rotatable electrode, means supporting a flexible endless blade electrode in contact therewith for marking a recording medium therebetween, said means including a plurality of rollers supporting the blade electrode with a loop projecitng from the rollers at each end, a stationary member disposed at each of said loops to prevent extrusion of the blade from be tween said rollers, and spring members uniformly distributed and closely spaced to each other directing pressure perpendicular to one face of the blade electrode to maintain a low mass-to-spring ratio and high resonant frequency at the point of said contact of the electrodes.

6. A recorder comprising a rotatable electrode, means supporting a flexible endless blade electrode in contact therewith for marking a recording medium therebetween, said means including a plurality of rollers supporting the blade electrode with a loop projecting from the rollers at each end, a stationary member disposed at each of said loops to prevent extrusion of the blade from between said rollers, spring members uniformly distributed and closely spaced to each other directing pressure perpendicular to one face of the linear electrode to maintain a low mass-to-spring ratio and high resonant frequency at the point of contact of the electrodes, and a plurality of spring elements uniformly distributed and directing pressure parallel to said face of the blade to effect uniform erosion of the blade.

7. In a recorder, a movable endless blade, a plurality of rollers supporting and driving the blade lengthwise with a loop thereof projecting from the rollers at each end, the stiffness of the blade providing driving friction for the rollers, and a stationary member disposed at each of said loops to prevent extrusion of the blade from between said rollers.

8. In a recorder, an endless blade electrode, a plurality of rollers supporting and driving the blade lengthwise with a loop thereof projecting from the rollers at each end, a stationary member disposed at each of said loops to prevent extrusion of the blade from between the rollers, and uniformly distributed spring means directing pressure on an edge of the blade to effect uniform erosion at the opposite edge.

9. In a recorder, an endless blade electrode, a plurality of rollers supporting and driving the blade lengthwise with a loop projecting from the rollers at each end, a stationary member disposed at each of said loops to prevent extrusion of the blade from between the rollers, and uniformly closely spaced spring elements directing and distributing pressure perpendicular to a face of the blade to limit vibration of the blade.

10. In a recorder, the combination comprising a rigid rotatable electrode, a flexible blade electrode having an edge disposed in sliding contact with the rotatable electrode for electrically marking a recording medium therebetween, said blade being subject to high frequency vibrations and wear, a plurality of closely spaced flat spring fingers disposed substantially parallel to one broad side of the blade electrode and directing pressure on said side to limit said vibrations, and means for advancing the blade electrode in both lengthwise and transverse directions thereof to compensate for wear.

11. In a recorder, the combination according to claim 10 wherein said means includes a plurality of spring loaded arms disposed parallel to said side and directing pressure parallel thereto in said transverse direction.

References Cited in the file of this patent UNITED STATES PATENTS 2,212,970 Finch Aug. 27, 1940 2,380,467 Ressler July 31, 1945 2,615,777 Deuth Oct. 28, 1952 2,621,999 Alden Dec. 16, 1952 

